Charges over alleged corruption in North Island prisons are in the news again, as reported by RNZ. Contraband, staff, pressure inside the wire. The question underneath is why those prisons are so full in the first place. And the answer isn't people who have been found guilty of anything.

It's remand. People locked up while they wait for their day in court. Stats NZ's latest figures put the 2025 total at 20,268 (Source: Stats NZ, remand-prisoners). That is up 3,819 on 2024's 16,449, a rise of 23 percent, and the single biggest year-on-year increase in the 27 years this series has been running.

Here's how we got here.

In 1998 the count was 4,497. By 2003 it had doubled to 9,243. By 2006 it passed 11,000. That first decade was steep, but it was also the era when the whole justice system was expanding.

Then something interesting happened. Between 2010 and 2013 the number actually fell, from 12,273 to 10,962, a drop of nearly 11 percent. Remand was going backwards. It happened without ceremony.

The reversal started in 2015 and it was brutal. From 10,962 in 2013 the count climbed to 13,857 in 2016, 15,801 in 2018 and 17,022 in 2020. That's a 55 percent increase in seven years. This is the period when bail law tightened and the presumption shifted. The remand population wasn't rising because more people were being convicted. It was rising because more people were being held before anyone decided whether they'd done it.

COVID broke the trend, briefly. 2021 fell to 14,727 and 2022 to 14,145, the lowest reading since 2017. Courts slowed, movements stopped, and the pipeline emptied a little. It didn't last. 2023 went back to 15,540, 2024 to 16,449, and then 2025 blew past every previous peak.

Add it up. Since that 2022 trough, remand numbers are up 43 percent in three years. Since 1998, they've more than quadrupled. New Zealand's population has grown over that time, but nowhere near four and a half times.

This matters for a reason that goes beyond bed counts. Remand prisoners are, legally, innocent people. They can't do rehabilitation programmes properly. Many are held far from home. Some are eventually released without conviction, or sentenced to less time than they've already served. And every extra body puts pressure on staff, on facilities, and on the systems that are supposed to stop contraband and corruption taking hold.

So when the political conversation turns to whether we're being tough enough, hold this number in your head. The toughest thing we currently do, at scale, is lock up people who haven't been found guilty. In 2025 that happened 20,268 times.

The 2025 figure is the most recent available. If the trend of the past three years holds, the next one will be worse. Prison capacity isn't a crime story. It's a bail policy story, and the data has been shouting it since 2015.